A goal of data visualization is the creation of visual representations of data, for example in the form of graphs, plots, and information graphics, which make data easier to understand and more useable for the viewer. Pie charts are data visualization tools that can convey information through slice color, position, and ratio. A pie chart is typically a circular (i.e., pie-shaped) chart comprising one or more sections, or “slices,” each of which represents a defined percentage of the entire chart. The values represented by respective slices can be said to rely on each other, because together the values sum to 100 percent. In an example, a pie chart conveys information concerning the favorite colors reported by a class of 100 students and initially comprises a seventy-percent “green” slice (if seventy students report that their favorite color is green), a fifteen-percent “red” slice, a ten-percent “yellow” slice, a five-percent “blue” slice. In this example, if ten “green” students change their minds and report that blue is actually their favorite color, the “green” slice shrinks to fill sixty percent of the pie chart and the blue slice grows to fill fifteen percent of the pie chart.
A threshold is a value at or beyond which a measure (e.g., an intensity of a stimulus, a temperature, a percentage) becomes significant for a defined reason. For example, at or below thirty-two degrees Fahrenheit, water freezes; at or above 212 degrees Fahrenheit, water boils; and at or above a defined market share, a firm can be comfortable with its position.